Sealed silent winch

ABSTRACT

A hand-operated winch designed for marine craft and in particular for use as a sailboat sheet winch is disclosed. All braking and bearing elements are sealed and not exposed to the elements. It includes silent one way clutches as opposed to conventional pawl escapements for braking. Several different winch diameters may be produced using a common working mechanism since the drum is separable from the working mechanism. Dual thrust rings allow axial loads to be sustained.

United States Patent Baldwin et al.

[ 1 Feb. 15, 1972 [54] SEALED SILENT WINCH 2,836,085 5/1958 Snyder..254/187 UX [721 Inventors: William 0. Baldwin, Anaheim; Theodore 5:32;"321x33 y westminister both of Calif. [73] Assignee: Plasmachem lnc.,Newport Beach, Calif. FOREIGN PATENTS 0R APPLICATIONS 182,226 7/1922Great Britain ..1 14/1 1 i [22] 1969 527,743 10/1940 Great Britain...2s4/150 [2]] Appl. No.2 842,428 731,014 3/1966 Canada ..254/150 PrimaryExaminer-Harvey C. Homsby {g 254/186 Assistant ExaminerMerle F. Maffei 0l e I e e e n n e n n n I e e n n e e n e e n e n e e e e n n u u a v ve e e e e n e e J h E. w 153 Field of Search ..254/150, 187, I80 HC,184; agner ll4/lll;2l4/l32 57 ABSTRACT 5 R f n Cited A hand-operatedwinch designed for marine craft and in particular for use as a sailboatsheet winch is disclosed. All brak- UNITED STATES PATENTS ing andbearing elements are sealed and not exposed to the elements. It includessilent one way clutches as opposed to James conventional p escapementsfor Several different 755953 3/1904 f winch diameters may be producedusing a common working 1,570,061 [/1926 Henr'cksm mechanism since thedrum is separable from the working 8 i mechanism. Dual thrust ringsallow axial loads to be sustained. o 2,501,096 3/1950 Robins et al...254/187 X 1 Claim 8 Drawing Figures SEALED SILENT WINCH BACKGROUND OFTHE INVENTION Winches for handling lines on marine craft in particularsailing boats have traditionally employed a mounting base, some type ofescapement or one-way brake and an outer drum with a reduced diameterwaist for holding a number of turns of working lines. Hand winches oftenemploy a socket at the top for mounting a crank handle for manualoperation.

Because these winches are mounted on the weather deck of low-freeboardvessels and exposed to extremely arduous conditions the workingmechanisms are subject to submersion and damage from corrosion. Theinternal mechanisms are therefore designed to be as simple and corrosionresistant as possible. The traditional spring-loaded pawl and star gearhas been used for many years as the brake mechanism of the hand winch.Despite the simplicity of the traditional design existing winchesrequire necessary servicing or lubrication because the locking mechanismis exposed to water leaking either from the top crank opening in certaincases or under the drum. In some cases the base of the winch i'scup-shaped and it actually traps and holds seas.

One further limitation on existing winches relates to their internaldesign. Since winches are designed to accept tangential loading, little,if any consideration has been given to axial loading. In certain winchesonly a light assembly screw sustains any axial loading.

Another and extremely important deficiency in prior art winches is thefact that the conventional pawl-locking mechanisms often constitute thenoisiest piece of working gear on a sailboat. Where the boat is used forracing, the characteristic chatter of a pawl winch is the signal tocompetitors that the boat is undergoing a manuever. Often the matter ofa few seconds in making a manuever can make the difference between winand loss in a race and the signaling to all within ear shot of amanuever by the noise of the winch is totally unnecessary. This isparticularly true during overnight racing where the contestants cannotsee sail movement.

A further slightly less glamorous consideration is that in prolongedsailing voyages where manuevers from sail handling must occur at allhours, the operation of conventional winches is disturbing to sleepingcrewmen.

BRIEF DESCRIPTION OF THE INVENTION In view of the foregoing deficienciesin the prior art, there is an object of our invention to produce acompletely sealed mechanism winch which is not subject to the damage byexposure to normal-operating marine conditions. The second object of ourinvention is to provide a winch which is silent. A further object of ourinvention is to provide a winch which includes no areas which will trapwater internally.

Still another feature of this invention is a novel dual-thrust ringassembly which absorbs axial loading on the winch.

One further feature resides in a highstrength low-weight drum which isinterchangeable to provide variable size winches using a common workingmechanism.

BRIEF DESCRIPTION OF THE DRAWINGS These and other features of thisinvention may be better understood from the following detaileddescription and by reference to the drawing in which:

FIG. 1 is a perspective view of a hand winch of this invention;

FIG. 2 is a partial vertical section through the body of the winch ofFIG. 1 showing the working mechanism;

FIGS. 3, 4 and 5 are sectional views of three different size winchesusing the same working mechanisms;

FIG. 5a is a fragmentary section of the assembly of FIG. 5 taken alonglines 5a5a of FIG. 5;

FIG. 6 is a perspective view of a sprag clutch constituting the brakingmechanism of this invention; and

FIG. 7 is an enlarged fragmentary diametrical sectional view of thesprag clutch of FIG. 6.

DETAILED DESCRIPTION OF THE INVENTION Now referring to FIG. 1, a handwinch 10 in accordance with this invention has the general exteriorappearance of prior art winches including a drum 11 having an enlargedbase 12 and a reduced waist portion 13 which may be a smooth, slightlytapered surface, or roughened for increased friction with lines to behandled. At the upper end of the drum 11 is a cap 14 of slightly smallerdimension than the base portion 1' and having a central socket 16 forreceiving a handle 15. The cap 14 and drum 11 are preferably separablemembers in accordance with this invention.

The winch 10 of FIG. 1 includes an internal one way clutch or brakingdevice which allows a line to be drawn up by operation of the handle inone direction, for example, clockwise as shown in the drawing andprevents and resists unwinding in the counterclockwise direction. Atypical application of a winch of this type is in handling the sheetlines of a sailboat. In certain cases the handle 15 may include a doublehandle to allow two persons to work together in drawing up a line underheavier load conditions.

As shown in FIG. 1, the winch has all the appearances of conventionalprior art winches designed to take lines and circumferentially aroundthe waist portion 13 with tangential loading of the drum in thedirection of the dashed line a in FIG. 1. We have found, however, that awinch having a substantial lip on the cap 14 is a natural place forattaching lines for lifting. For example, in the case of a submerged orpartly submerged boat where some lines must be attached to raise theboat. In such case the winch is subject to loads in a general axialdirection typified by the dashed arrow 6 of FIG. 1. The winch inaccordance with this invention is designed to accept all required loadsin either of the above two directions or with components in eitherdirection.

For an understanding of the mode of operation and internal workings ofthe winch of FIG.. 1, now refer to FIG. 2 showing the winch partially insection. In addition to the drum 11 and cap 14 of FIG. 1 a concealedbase 20 may be seen. The base includes a number of screw holes 21, oneof which is shown designed to receive flathead screws for mounting thewinch on the deck. Since the winch is also designed to accept axialloads, the mounting plate 20 may include a matching backing platedesigned for under deck mounting and in such cases the flathead screwsintended for holes 21 would be replaced by flathead machine bolts. Inany event the mounting plate 20 includes a riser portion 22 withinternal threads 23 mating with a central shaft 24 constituting theheart of the drive mechanism of the winch.

The shaft 24 includes an integral braking surface 25 having a diameterof approximately double of the body diameter of the shaft 24. Above thebraking surface of race 25 is a longer medium diameter portion 26 with athrust ring groove 30 and a step 31 joining a reduced diameter endportion 32. This end portion 32 includes a second thrust ring groove 34and end step 35. I

A first sprag-type clutch 40 encircles the braking surface 25 with theinternal surface of the sprags of clutch 40 hearing on the surface 25.The outer ends of each sprag member bears on an encircling sleeve 43.The center portion 26 ofshaft 24 constitutes the support for the innerrace of a pair of ball bearing assemblies 41 and 42 which have theirouter races positioned on steps of sleeve 43. The lower ball bearingassembly 41 is positioned between the upper edge of the surface 25 andan internal shoulder 44 of sleeve 43. Bearing assembly 42 is restrainedfrom axial movement by the shoulder 44 and a thrust ring 45 in groove30.

A second one way clutch or braking device 60 between cap 14 and the drum11 allows the handle 15 (of FIG. 1) to be turned in a counterclockwisedirection free of the drum to obtain the equivalent of ratcheting of thehandle. This one way clutch 60 also allows the drum to free wheel withthe handle held by the user.

The second thrust ring 46 in groove 34 retains a belleville washer 51bearing against a lip of a two-part sleeve 50. The

sleeve includes an inner bronze bearing which is shown of generallyLushaped in the drawing and an outer hardened steel surface whichconstitutes the internal braking surface for the sprag clutch 60. Thesleeve 43 provides the outer braking surface for the sprag clutch 60.

The belleville-type washer 51 and bearing against sleeve 50 appliesaxial loading of the cap assembly against the step 31 of the centralshaft 24. This axial loading is just sufficient to hold the cap (andhandle, if installed) when the drum is freewheeling. Any operating forceapplied by the operator to the handle overcomes the frictional loadproduced by the belleville washer 51 allowing the handle to drive thedrum 12 and cap 14 in a normal manner. This feature eliminates anyfreewheeling of the cap and handle which can be dangerous to nearbypersonnel.

The sleeve 50 at its upper end is internally threaded 61 to receive acapnut 66 having internal recess 62 for receiving a handle. The capnut66 is sealed by an O-ring seal 63 to the cap 14. The cap l4 is sealed tothe drum 11 by a fiat washershaped seal 64 which may be of neoprenematerial. The base 20 and drum 11 are sealed against the entrance ofmoisture into the working mechanism by a similar seal 65.

The winch as shown is designed to rotate freely in one direction; forexample, clockwise on the ball bearings 41 and 42 while restrained fromrotating in the opposite direction by the sprag clutch 40. The sleeve 43which is shown as a separate part from the drum 11 is secured thereto sothat in operation the drum 11 and sleeve 43 move as a single part. Inthis manner the drum moves freely in one direction and is securelylocked by the sprag clutch 40 from movement in the opposite direction.The entire mechanism is contained within the seals 64 and 65.

In installation the base 20 is first installed using screws throughholes 21 and the capnut 66 is removed exposing a screwdriver slot(unshown) in the end 35 of the central shaft 24. Using the screwdriverslot, the central shaft 24 is threaded into the base 20 to mount thewinch and then the cap plug 66 is reinserted into the cap 14. The winchis then installed with all seals in place and ready for operation.

In the case of immersion of the winch, the entrance of any water intothe working mechanism is prevented by the seals 64 and 65. Where thepassage is between the cap 14 and drum 11 or between the drum 11 andbase 20 the surfaces are slightly tapered outward and downward to permitany water entering the winch to run out freely without being retained orreaching the working mechanism.

It should be noted that in FIG. 2 that drum 11 is separate from thesleeve 43 but the two operate as a single member when the winch is inuse. The drum 11 and sleeve 43 during the manufacturing process may bepermanently joined together as by welding or secured by a number oflongitudinal splines not shown in the drawing. In either case the winchin its final assembly form is made up in two separate parts. The reasonfor the separate construction of these two parts is more clearlyapparent in FIGS. 3, 4 and which also illustrate another feature of thisinvention.

Referring now to FIGS. 3, 4 and 5. FIG. 3 in which the central shaftbearing and sprag clutches are removed and the sleeve 143 correspondingto sleeve 43 of FIG. 2 may be seen including the same stepped internalring surfaces designed to receive a sprag clutch at each end, the ballbearings on the next level and the latter being retained from axialmovement by a central annular shoulder. Encircling the sleeve 143 is asecond sleeve 144 which may be press fit or otherwise secured to ring143. In this case the drum is made up of a pair of flared bell portions120 and 121 joining the center of the narrow waist portion of the drum.These flared drum portions are preferably manufactured by rolling orspinning from stainless steel tubing. By comparison with FIG. 1, it canbe seen that there is significantly less metal in the drum assembly ofFIG. 3 compared with that of FIG. 2. This can produce a significantlylighter weight winch. Also the two drum parts can be produced byroll-forming, spinning or other manufacturing process which can be lessexpensive than forging or machining in the case of the structure of FIG.2. In the region where the radial forces are applied to the winch thedrum parts and 121 are backed by solid material of sleeves 143 and 144providing the same degree of strength as the drum assembly of FIG. 1.

with the basic diameter of the winch increased from D] to D2 I as shownin FIG. 4. Of course a larger pair of drum halves are required. FIG. 5shows even a larger winch produced with the same mechanism and a largersleeve 343 encircling the central sleeve 143 to produce a winch ofdiameter D3. In this case the sleeve 343 should have lightening holes asshown or spokes as shown in FIG. 5a.

A prime feature of the invention resides in the silent, but ef fectivebraking system employing the sprag clutches. A design of such clutchesis more clearly illustrated in FIG. 6 as including a number ofindividual sprags 40b loosely restrained in one or more slotted rings40a. The sprags include an outer and inner working surface and areloosely mounted in the ring 40a for slight pivotal movement. The spragsare pitched slightly with respect to the diameter of the ring 40a andthe outer surfaces as illustrated more clearly in FIG. 7 are curved.With the eccentric mounting in the curved surfaces the sprags tend toallow relative movement between an outer andan inner.enclosed race orbraking surface. Thus the sprags have a preferential direction ofmovement as is clearly indicated in FIG. 7. As shown there, the sprags40b allow relative movement of the outer race with respect to the innerone in the direction of the arrow. Whenever relative movement in theopposite direction is attempted the sprags tend to straighten to aradial alignment position and effectively lock the two races frommovement. In a typical l8 sprag clutch, a braking force in the order of400 ft.-lbs. is easily developed. With such clutches a winch having adiameter of three inches can provide a tangential braking force of 2,500to 3,000 lbs. and is virtually free running in the opposite direction.

From the foregoing it may be seen that we have produced and improved awinch in which the working mechanism is entirely sealed herebyincreasing the life and minimizing, or eliminating maintenance. Thewinch also employs no pawl mechanisms; instead silent sprag-typeclutches which constitute effective brakes in one direction. The centralshaft of the winch includes two thrust rings designed to transfer axialloads on the drum and cap to the shaft whereby the winch is capable ofsustaining axial loads at least as great as the normal tangentialbraking force. The winch includes a sleeve member containing the entireworking apparatus whereby the final diameter of the winch may be changedmerely by adding additional encircling sleeves and an outer drum. Theouter drum is shown as a form tubular member in order to minimize theweight while maintaining the required strength.

The above described embodiments of this invention are merely descriptiveof its principles and are not to be considered limiting. The scope ofthis invention instead shall be determined from the scope of thefollowing claims including their equivalents.

We claim: 1. A deck winch comprising: a base for mounting on a deck; anupstanding shaft mounted on said base; a drum including an outer surfacefor holding working lines and an inner coaxial surface; bearing meansengaging said shaft and inner coaxial surface of said drum for mountingsaid drum for rotation about said shaft; a first sprag clutch encirclingsaid shaft and in one-way braking engagement with said shaft in drum;

a separate cap for said winch overlying said drum and including a closedend socket recess for insertion of a handle to drive said winch;

said cap including a tubular sleeve portion encircling said upstandingshaft and in rotational engagement therewith;

a second sprag clutch engaging the outer surface of said tubular sleeveportion of said cap and an inner surface of said drum whereby said capand drum are engaged for one-way driving of said drum by said cap;

said first and second sprag clutches oriented for braking in oppositedirections whereby said cap applies driving force

1. A deck winch comprising: a base for mounting on a deck; an upstandingshaft mounted on said base; a drum including an outer surface forholding working lines and an inner coaxial surface; bearing meansengaging said shaft and inner coaxial surface of said drum for mountingsaid drum for rotation about said shaft; a first sprag clutch encirclingsaid shaft and in one-way braking engagement with said shaft in drum; aseparate cap for said winch overlying said drum and including a closedend socket recess for insertion of a handle to drive said winch; saidcap including a tubular sleeve portion encircling said upstanding shaftand in rotational engagement therewith; a second sprag clutch engagingthe outer surface of said tubular sleeve portion of said cap and aninner surface of said drum whereby said cap and drum are engaged forone-way driving of said drum by said cap; said first and second spragclutches oriented for braking in opposite directions whereby said capapplies driving force from said cap to said drum when said cap is drivenone direction and said drum is braked from rotation in the oppositedirection wherein said upstanding shaft includes two step portions and aretaining groove in each step portion; a thrust bearing ring secured toeach the first and second step portion of said upstanding shaft; one ofsaid thrust bearings engaging said tubular sleeve portion of said cap;and the second of said thrust bearings engaging said drum.